Door latch



Dec. 1, 1953 B. N. CARLSON 2,660,765

DOOR LATCH V Filed Jan. l5, 1950 IN V EN TOR.

? CQQLSON,

TOE/VEV- Patented Dec. l, 1953 UNITE eras Ziitii .ares 'eric The present invention relates to door latches in general and particularly to a latch for overhead doors. More specifically the invention comprises a latch for overhead doors which automatically retains the door in an open position and which is releasable upon the pulling of a release cord hanging downwardly through the door.

The overhead door is widely used, particularly in garages. Its characteristics are such that a door of relatively great height, length and weight can be opened in a single operation, the presence of counterbalancing springs materially reducing the force required from the operator. Usually such doors in their closed position extend vertically and are substantially in alignment with, or at least parallel to, the iront wall of the garage or building of which they are a part. In their raised or open position they er:- tend horizontally, or substantially so, and are at a sunicient height that persons and/or vehicles, such as automobiles, can pass thereunder.

It has been the experience of users that while overhead doors are. opened with surprisingly little effort, and this is because of the presence ci the counterbalancing springs, yet the eiective counterbalancing of the forces and weights frequently produces a balance so sensitive that the door is sometimes displaced accidentally from its raised open position by vibration or by the force of wind. Stated differently, the establishment of a sensitive balance between the counterbalancing spring and the weight of the unit too frequently results in a, condition of unstable equilibrium with the door raised. While this could be overcome in certain instances by increasing the strength of the counterbalancing spring, or hy placing additional weights on the door at proper positions, such a step would adversely aiect the relationship. making the door easy to handle.

With an appreciation of the usefulness and operating characteristics of overhead doors it is a primary purpose of the present invention to provide a latch for overhead doors which automatically retains them in their raised open position against accidental displacement.

A further object of the present Ainventionuis to provide a latch for overhead doors which comprises elements upon the door and upon the building which cooperate to eiect positive locking action to retain the door in its raised open position, and which is releasable by the user upon pulling a release member extended downwardly through the door.

Cil

Still another object of the invention is to provide a latch for overhead doors which functions not only to prevent a door from pivoting downwardly, but which also is adapted to support a part of the Weight o1" the door in the raised open position.

These and other more specific objects will appear upon reading the following specification and claims'and upon considering in connection therewith 'the attached drawing to which they relate.

Referring now to the drawing in which a preferred embodiment of the invention is illustrated:

Figure l is a vertical section through a building incorporating a pivoted overhead door retained in its raised open position by means of a latch constructed in accordance with the present invention;

Figure 2 is'an enlarged showing of the doorretaining latch illustrated. in Figure 1 in its locking relationship;

Figure 3 is a viewflookng in the direction of the arrows upon the line 3--3 of Figure 2; and

Figure'4 is a showing similar to Figure 2 but withv the latch pivoted to release the door under an operator-provided force.

In the drawing, and in Figure i in particular, an overhead door is illustrated pivotally mounted in a doorway in the wall of a building. The latter is indicated generally by the reference character lil, the door generally by the reference character li, and the latch unit, comprising'the present invention, is indicated generally by the reference character l2. of any type andV made of 'any conventional inaterial, it` being important'only thatit be provided in one wall with adocrway such as is indicated generally by the reference character i3. The doorway shown in Figure Y1 includes side vmembers 514,- ofi 'whichone is illustrated, and 'a transverse topfniember i6?. The front wall fof Vthe building is indicated generally by the reference'charactjer l1, and -its roof by thev reference character Hh;V 7 Door Il may be 'of conventional vsise and sha-pe, -for example,4 about `12E-Atol 15 feet long andabout '7 feet high. It may be of wood or metal and should have sunicient rigidity as'to j maintain itself in a single plane in both the vertical and in the horizontal positions. In the illustrated form the door includes side frame members 2! connected cy cross-members 22 over which lie the face or wall 23.

Each end or side of vthe door is pivotally sup- The building maybe Y ported for movement between a vertical position, in which it is even with the front of the doorway i3 and closes that aperture, and an upper, raised or open position, as illustrated in Figure l. The pivotal mounting at each end comprises a pair of spaced arms 26 and 27 xedly connected at one end to a member 28 affixed to the door frame member 2|. At their opposite ends armsZ and 21 are pivoted.onmaebracket 29 secured xedly totherside memberv M: or" the. doorway.

The arm 2B at each end of the door is extended. beyond its pivot on bracket 29 and is provided With a plurality of openings 3| adapted to're.- ceive and seat one end of an elongated coil ,springl 32 the opposite end of which is suitably secured; as by a bracket 33, to the doorway sdemember lli. Spring 32 at all times exerts a pivotal force upon the arm, tending to raise door I'from its vertical to its horizontal position. With the door in the latter position the spring exertslaforee on its connected arm dto'retailn the-dooragainst accidental downward displacementv The-pres-y ence of a plurality of spaced holes 3| along the arm 2E, each adapted to seat 'thefendf of thefcon-f nected spring 32, makes it possible teL vary'v thespring force and its effective lever armabout the pivot point of arm 2E. It is` possible to. so` tension the springs 32 thatthe force. required tow-litt the` door is minimized, Vbut-'the difficulty vlies` inthe fact that when the balance is accurately estab1- lished theforce which: thetspring exerts: in: retainingthe door in itsraised position, as ilflustrated in Figure 1, is frequently too smallf'and the door may accidentally-pivot .from itsopen to its closed position.

The latch unitv ZrOnstructedf'irr.accordance with the present invention comprises a'leaseiplatel 35 secured by screws 31 to the buildingvwall ll; Integral parallel plates:Esfextendtoutwardly'from baseV plate 35', each'` being.: formedfwith: a: lower edge 39 which slopes downwardly and-outwardly.' One.: plate .38. is. formed? with'a; transverse tlip .4 i which: extends across tos-the'.-adjacent'rplateftd provide'arstop; aswi'llgbe described.;` Between the piates. txtheelatch: lf is: pivoted' upon; ai: pirate-rl" extended therebetween; Hatch'A'sfextendsfabove and: below pin lll,- being formedeadjacentpthe curvedisurfaces' with azsh'eul-der-- below-which;

extends yits owncurved' s-urfeefelvv conforming,

limiting: angular position; Onwits: side-spaced from thestep it is` formed-withsan outwardly projecting nippleY 54 whichseats one end Lot a coil spring 52 the' opposite-endefwhich seats upon. a pin 53 Aca-rriedi-.by `base-plate 3.8, Ooit spring atr alltimes urges-Jeverorflatchaf clockwise di-rectiongaseviewedjn Egures2 and. (if to; cause its` upper. end to. abut. theestop dit When: soepositionedi shoulder,v 4.8; projects. beyond thecurved edgee oftheaplatesiS. A secondl coil spring 54 encircles the vp ivottpin...4l:and.r through engagingoneof the plates38 at .onepf' its ends andn the latchzllfat -the.other exerts ampliaoting force. supplemental to-.lthat ot spring 52',V

The latch unit baseplata-f3(ir-is-v secured-.tothe wall l1 of thel building directlyabove; andepref-l erably centrally oithedoorwayv so: that the latchv 136 extends vertically with its lpivot pirrll "andi its shoulder i8 horizontal-fasfillustrated"in' the drawing.

Carried-'by the fronvface oith'edoor Hand positioned thereon as to move into cooperative relationship with the latch 4S is a hook 55 formed at the outer end of an offset arm 5l' of a plate 58 secured by screws 59 to the face 23 of the door. The oset arm 5T is so located on door ll that with the door in its raised position the arm is positioned immediately forward of the building front wall il, and its length is such that when so positionedthe end of thehookti overlies shoulder 8^,ofiatch plate-lie; Pivotailymounted upon the hook plate 53 is a release plate ill which is, V-shaped with its apex roclingly connected for pivotal movement by a pin or pins 62 at the angl-e; between the arm 5i' and plate 58. The end ofthe release lever or plate el extends just shortof the end of hook 56 and in position te Contact thecurvature et' of the plate e immediately adjacent the shoulder it with the heel; and latch-engaged. This relationship is most clearly shown in Figure 2. The` force exerted by springs 52 and 56. acting through, the latch @-5 holds the releaselever in the position illustrated in. Figu-re 2;

The lower end o release plate or lever el ex"- tends adjacent the plate e3, and with the lever in` its normal engaged: position, a5..illustratedin Figure. 2, it is spaced therefrom angularly shown in Figure An eye bolt t3 extendgupwardly`v through aperture. te in the door face 23,1 and `aligned apertures 65 and 5l' in the plate and lever El, respectively` A nut t8 seated. upon. the threaded upper/.end of eye bolt 63 rests upon .latch plate Si whilev a cord et is attached toits lower end and hangs below the doory illustrated in Figure l. The.; cord should. have a suf'cient length that a person stand-ingv upon` tlle'ii'oor can reach. upward-ly and grasp it. The weight of, eye bolt. t3 and connected cord S9 acting. throughv the lever platel El is not sufficient tospivot the: latter: to dispiace the latchrit from hook 55 against `the force exerted by coils-prings.

'Die operation oi thelatch constructedfgin:accordancew-ith the present'invein tiorrwhenincorporated.in an. overhead door is as follows` Let it ,be-assumedthat the door il is rst. in; a vertical position in3 which. it closes doorway: I3 *and its giace 2311s parallel to the fac i? offthebui-lding, Ii it is desired to .open the door i an upward force is exertedV upon the outwardly extendingerigid arm 5?*- of hook plate 58 which.

withthe door in a vertical position, functions as ahandle and. extends horizontally and at a. convenient height to receive-the lifting force. The liftingforce, supplemented by the counterbalancing effect of. the' coil springs 32 at its opposite ends, causes the door to swing upwardly, the arms 26'V and 2l pivoting about their pivotal connectionson their. brackets, 253; As the doorzinoves into itss-.raised horizontal.Y position, as. illustrated;

in Figure l, the curved roundedend of Vhoolltll contactsthefdownwardly and. outwardly projectinggcurvedsurface t9: ofpivotedxlatch The movement; of ther hoch-is. primarily vertical at Y this arcfof the'd'oors travel and as it. moves upwardiyfitcamsrthe curved? edge i9 of the llatch to the right, as viewed'in' the drawing, sov that that edge approaches parallelism with thefcurved edges 3S of side plates` 38e." The hook 56 continuesits upwardV travel until its hooked end' passes l'atcl'r shoulder'Y 48 whereuponv the latchl is immediately pivoted undervthe urging of coil springs 52'? and 54. The shoulder'll moves under the downwardly-`A extending end of hook 5E, at the same time forcing release plate.' Si' Vtoy the position in which its lower portion is spaced from the plate t, as shown in Figure 2. In the latter relationship, it is to he noted, the door cannot pivot downwardly for the lower' end of the hooi; the shoulder lill. The downward iorce thus exerted is apposed by the latch which is carried i y s pivot pin il almost immediately thereaoove.

Let it be assurned that it is desired to lower the door. A downward force on the door itself would not produce the desired result because of the engagement or the hoot; 55 with the latch shoulder t?. To effect the release of the door a downward force is exerted upon the cord or rope te. That force is transmitted through the bolt B3 and nut 53 to release'lever or plate El to pivot it in a clockwise direction until it abuts hook plate 5S, a position illustrated in Figure Il. The upper end or release plate ti in this movement forces the latch llt in a counterclocirwise direction from the position illustrated in Figure 2 to that illustrated in Figure 4 in which the shoulder lil no longer underlies the hook 5%. A continued downward force upon the cord 6?# pulls the end of the hooi; past the latch shoulder ld whereupon the door is free to continue its downward pivotal movement. The operation can, of course, be repeated.

The latch of the present invention functions not only to retain the overhead door against accidental downward displacement 'out also functions 'to prevent sagging. Such doors oeing relatively long tend to sag in the middle in their raised position and this frequently results in permanent warping. The latch of the pr sent invention prevents the pivotal movement of the door and additionally, through the cooperation of the pivoted latch it and the hook 55 in their engaged relationship, prevents downward sag. The hook 5t engages the latch shoulder t@ al'- most directly under the pivotal airis il ci the latch so that the downward weight of the door provides no pivotal movement in the latch and instead the latch functions as a support.

While the particular apparatus herein shown and described in detail is fully capable of attain ing the objects and providing the advantages hereinbeiore stated, it is to be understood that it is merely illustrative or" the presently pra ierred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as defined in the appended claims.

l claim:

l. En an overhead s vinging door construction, a frame forming a doorway, a formed with an aperture pivotally mounted in said doorway for pivotal movement between vertical closed and horizontal raised positions, a pivoted' latch mounted on sa, frame above said doorway, a hook :Fixed tc the forward face of said door at a position to move into overlying engagement with and to he supported by said latch with said door in its raise-d position, and release means carried by said door to pivot said latch to release said hoolr and including a cord hanging downwardly through the aperture in said door with said door in its raised position.

2. In an overhead swinging door construction, a frame forming a doorway, a door pivotally mounted in said doorway for pivotal movement between vertical closed and horizontal raised positions, a spring-pressed pivoted latch mounted on said frame immediately alcove said. doorway, a hook fixed to the forward face of said door in through which an actuating force can he exerted on said release lever.

3. In an overhead swinging door construction. a frame forming a doorway, a door pivotally mounted in. said doorway for pivotal movement between vertical closed and horizontal raised positions, a spring-pressed pivoted latch including a normally horizontal shoulder and a curved ap preach surface adjacent thereto, a hook xed to the forward face oi` said door in a position to move substantially vertically into contact with the curved approach surface of said latch to cam the latter aside as said hook moves above said latch shoulder, said latch pivoting under its spring pressure to position said shoulder under said hook to support it and the attached door, a release lever carried by said door and positioned as to be adjacent said latch with said hook over lying said latch shoulder, and a release element to actuate said release lever to pivot said latch and displace its shoulder from under said hook to permit said door to swing downwardly.

4. in an overhead swinging door construction, a frame forming a doorway, a door pivotally mounted in said doorway for pivotal movement between vertical closed and horizontal raised positions, a spring-pressed pivoted latch including a normally vhorizontal shoulder and a curved approach surface adjacent thereto, a hook to the forward face of said door in a position to move substantially vertically into contact with the curved approach surface of said latch to cam the latter aside as' said hook. moves above said latch shoulder, said latch pivoting under its spring pressure to position said shoulder under said hook to support it and said door attached to it, a release lever carried by said door and positioned as to be adjacent said latch with said hooi; overlying said latch shoulder, and means to actuate said release lever to pivot said latch and displace its shoulder from under said hook to permit said door to swing downwardly, said means comprising an extension of said release lever extended adjacent the face of said door and normally held spaced therefrom by said lever in contact with said latch while in its latching position, and anl element connected to said release lever and ex tended downwardly through said door while a horizontal position and throughs-which a leveractuating force can be transmitted.

5. The construction recited in claim 4 characterized in that said hook is rigidly mounted on the forward face of said door and provides means by which a lifting force may be transmitted to said door.

6. In an overhead swinging door construction, a frame forming a doorway, a door pivotally mounted in said doorway for pivotal movement between vertical closed and. horizontal raised positions, a latch unit to retain and support said door in said horizontal raised position and including cooperating parts on said frame and on said door, the parts on said frame comprising a bracket positioned immediately above said doorway and including a base plate and parallel outwardlyV extendingvertical plates,- and aspring-v pressed latch pivoted4 between said vertical plates, the part on said door comprising arigidlymount ed hook so constructed and-so locatedon said door as to move into` over rg engagementwith said latch as said door l s into its horizontal raised position in order to beV supported by said latch and in order to support said door, and release means to pivot said latch from its-engage? mer-1t with said hook and; including an element connectedtov said latch and extend-ing. downwardly through said door.

7. Inan overhead swinging door construction, al frame, forming a doorway, av doorv pivotally mounted in saiddoorway for pivotalmovement between vertical closedandhorizontal raised positions, a pivoted latch mounted on said frame immediately above said doorway, a hookx-Xed to the front face of said door in a posi-tion tor move substantial-ly vertically into engagement with saidlatch during the nnal portion of the movement of said door into its raised horizontal position,

said latch being movable into position to 'overliesaid hook to receive a supporting force` and to' prevent the vertical downward displacement' of said hook'and the attached doo-r, andr a manually operable release unit to releaseV said latch. from said hook to permit said door to pivot downwardly.

8. In an overhead swinging door construction, a framev form-ing av doorway, a door pivotallyV mounted insaid doorwayA for pivotal movement between vertical closed and. horizontal raised positions, a pivoted latch mounted on said frame immediately above said doorway, a hook fixed to. the front face of said door ina position tc'move substantiallyvertically'into'engagement with said latch during theY nal portion of the movement oi said door into its raised'horizontal position, said latch being movable into 'position to over'- lie said hooi; toY receive a door-supporting' force and,` to prevent the vertical downward displacement ,of said hooi; amlltheY attached Adoorga re,- leaseleverv carried by'said door to pivot said latch from its'overlyi'ng relationship tosaid' hoolntand a member connected to sai'd release lever extend-V ed downwardly through said. door adapted' to receive a downward force to lactuate said releasef lever and thereafter to pivot said door down'- wardly.

9. A latching mechanism comprising cooperating latch and hook units, saidlatch unit includ-- ingv a frame having a supporting base and spaced parallel plates secured to said base on one side thereof and forming an open-sided and open,-v ended housing, a plate-like latch pivoted between said parallel plates for pivotal movement a plane parallel thereto, said latch having a horizontal shoulder extended at an angle-'to aradiusv centeredon thepivotalaxis. of saidrlatch and also` said plates, the.end,-ofv said hook member being,-

adapted toextend horizontally over and rest upon said'shoul'der upon said latch-,being returned, to its initialposition vupon the-. hook memberpassingl said curvedapproach surface, said hook unit alsoincluding a pivotalv latch-displacing; lever having twowangularlyrelated runs one of which extendsI along the run of' saidv hook member adapted to-A be iixedly connected toy said bod-y and the other of which extends to a point adjacent the overhanging endof vthe other run of. said hookA member, said'lever being pivotally con,- nected to said hook member'for movement against the curved approach surface of said. latch to displace said latch shoulder from under the end of said hookv member to enable said Vlatch and' hook units to be relatively displaced,l and. a member to receive. a force from'an operator to effect the pivotal movement of said leven l0* The construction recitedin .claim 9 characterized in that said hook member and said lever are metal plate elementsrandi in that the includedlangle between the runs of said lever is less thanv the included `angle between the runs of. saidhook member;

1l The construction :recited 'in .claim l0. .characterized in.Y that- Isaid leverf member land said hook member are.vf pivotal'lyv connected at the apexes of the,Y included "angles ofvl their respective runs.

BOYD N; CARLSON.

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